This application for a Mentored Clinical Scientist Research Career Development Award (K08) is submitted by Elisabetta Patorno, MD, DrPH in response to PA-16-191. Dr. Patorno is a preventive medicine physician and pharmacoepidemiologist in the Division of Pharmacoepidemiology at Brigham and Women's Hospital, and Assistant Professor of Medicine at Harvard Medical School. With a rapidly increasing US population ? 65 years, who use the largest proportion of medications, a better understanding of the effects of medications in older adults as used in routine care is imperative. This need is even more acute for new drugs that usually enter the market on the basis of evidence from relatively small, short, and often placebo-controlled randomized trials (RCTs), in which older patients are often underrepresented or excluded. As a result, clinicians often struggle choosing the best treatment for their older patients, particularly those with frailty and multimorbidity. Dr. Patorno is committed to a career as an independent clinical investigator, focused on advancing research for rigorously monitoring the effects of medications in older adults as treated in routine care. To achieve this, Dr. Patorno proposes a 4-year program of career development and mentored research centered on the development of a valid system for timely and high-quality evidence on new diabetes drugs in older patients specifically tailored to address the unique aspects of care in older patients such as frailty and multimorbidity. This setting of research combines the urgent need for information on the effects of over 10 new antidiabetic agents approved by the FDA in the last decade with the need for the development of novel methods for prospective drug monitoring in real-world older adults. Within the highly productive and supportive research environment of the Division of Pharmacoepidemiology, Dr. Patorno will work with an interdisciplinary team of mentors and collaborators drawn from across institutions at Harvard University that have deep expertise and national/international reputations in the specific substantive areas of her proposed training: clinical geriatrics and diabetology, methods for prospective monitoring and data mining, and health services research in older populations. The overarching objective of her mentored research is to create and implement a novel approach for the near-real-time monitoring of the comparative safety and effectiveness of new diabetes drugs in older patients as treated in routine care. This novel monitoring approach will use Medicare claims data available with a relatively short lag time, linked to electronic medical records and the Medicare Current Beneficiary Survey. The proposed work will provide timely and actionable knowledge for clinicians treating older adults, defining the net incremental value of new antidiabetic agents in older patients with frailty and multimorbidity. The knowledge gained from this work will impact several million older adults in the US, and will provide the applicant with a solid background to become an independent researcher, and ultimately a leader, in the study of medication use and outcomes in aging populations.